Net Income per Ordinary Share - Weighted-Average Ordinary Shares Excluded from Computation of Diluted Net Income per Share (Details) - shares shares in Thousands	3 Months Ended
Mar. 31, 2019	Mar. 31, 2018
Exchangeable Senior Notes
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Ordinary shares (in shares)	5,504	5,504
Options to purchase ordinary share, RSUs and ESPP
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Ordinary shares (in shares)	4,988	3,305

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=6371337&loc=d3e3550-109257

Name:	us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration